Steam generating tubular water wall



E. C. CHAPMAN STEAM GENERATING TUBULAR WATER WALL Nov. 24, 1953 Filed Jan. 12, 1949 ATTORNEYJ Patented Nov. 24, 1953 STEAM GENERATING TUBULAR WATER WALL Edward Corbin Chapman, Lookout Mountain, Tenn., assignor to Combustion Engineering, Inc., New York, N. Y., a corporation of Delaware Application January 12, 1949, Serial No. 70,458

2 Claims.

This invention relates to steam generating continuous tubular water walls and similar members presenting a continuous water cooled surface for the protection of adjacent parts and particularly such as have relatively thin walled closely spaced tubes, and to a method of making such a wall.

In many installations in which steam is generated, either as the direct objective or as an incident to some other operation, it has been I customary to provide tubular water walls or similar parts presenting a continuous Surface and designed to cool and protect adjacent parts from corrosive gases and the like. Where the tubes are relatively large in diameter with relatively thick walls, or where the tubes are relatively widely spaced from one another, no difficulty is encountered in making the wall present a continuous surface through the use of fins and/or welding and in obtaining underwriters approval thereof.

In the case of relatively thin walled closely spaced tubes and also in the case of relatively small diametered thin walled tubes, it has heretofore been impossible, to the best of my knowledge, to provide a wall through the use of Welding which meets requirements, and the primary object of the present invention is to provide a wall presenting a continuous surface which will meet the requirements.

How the foregoing is realized is illustrated in the accompanying drawings, wherein- Fig. 1 is a partial vertical section through an installation having a circular wall embodying my invention;

Fig. 2 is a cross section through Fig. 1.

Figs. 3 and. 3a are enlarged sections of two adjacent tubes illustrating details of the inven-- tion and. the manner of welding, and

'1, the tubes in this instance having an outside diameter of substantially 1%" to 1 and a wall thickness of say %"i. The tubes may be composed of customary tube steel and, for illustrative purposes, the wall is shown as circular.

Referring now particularly to Fig. 3, it will be seen that in constructingthe wallI arrange the tube in close side-by-side relation, spacing adjacent tubes by means of a longitudinally extending spacing strip or strips 8. This spacing strip is of a thickness such that the root 9 of the welding opening or space H) is sufficiently wide as to permit of the laying of a seal weld or head in the space Ill which will not crack. In this instance the thickness of the strip 8 is substantially A,, giving a spacing between tubes, with the inner edge of the strip extending desirably slightly below a median plane, i. e., a plane cutting the centers of the adjacent tubes. It Will be observed that the location of the inner edge makes for a substantially deep welding opening. Also it will be noted that the opening is substan tially U-shaped as opposed to V-shaped as would be the case where the tubes were placed together without the spacing strip. By reason of the root thus provided, it is possible to have the arc reach the bottom of the weld opening and also to lay a nice uniform weld bead without fusing through the tube walls, which is particularly useful Where light or thin Walled tubes are employed. In Fig. 3a the weld bead II has been formed.

As thus far described, the arrangement is one in which access for welding is only had on one side. In Figs. 4 and 4a an arrangement is shown which is suitable for cases where both sides of the water wall are accessible for welding, and it is desirable to weld on both sides. In this case, the spacing strip 8a is of narrow width so as not to extend very much beyond either side of the median plane of the tubes.

It will be understood of course that the dimensions of the strip may vary, depending upon the diameter of the particular tubes employed. However, I have found that with small tubes, of the because of the sharp V as the arc will not penetrate to the bottom of the V. The root opening or a radius at the root must be provided in order for the arc to penetrate to the bottom of the groove.

I claim:

In a furnace, a water wall having its inner surface exposed for heat transfer and comprising: a plurality of relatively thin-walled tubes arranged in spaced parallel relation in the plane of said wall and each having portions exposed to form part of said inner wall surface; spacing strips extended between and parallel to adjacent tubes and each having edge portions respectively disposed both inwardly and outwardly of the median plane containing the central axes of the pair of tubes lying at each side of the spacing strip, the inner edge of each strip lying close to said median plane and the strip having a minimum thickness of approximately of an inch, said location of the inner edge and said thickness of the strip cooperating to provide a substantially U-shaped opening for the laying of a wel'd head; and welding beads in the welding openings uniting adjacent tubes, tube-to-tube each such bead overlying the inner edge of the spacing strip between a pair of adjacent tubes and having its inner surface lying between said median plane and the plane containing the innermost surfaces of the tubes to cooperate with the exposed portions of the tubes in completing the inner surface of the water wall.

2. In a furnace, a water wall having its inner surface exposed for heat transfer and comprising: a plurality of relatively thin-walled tubes arranged in spaced parallel relation in the plane of said wall and each "having portions exposed to form part of said inner wall surface; spacing strips extended between and parallel to adjacent tubes and each having edge portions respectively disposed both inwardly and outwardly of the median plane containing the central axes of the pair of tubes lying at each 'side of the spacing strip, the inner edge of each strip lying close to said median plane to minimize the space between each inner side of the strip and the surface of the respectively adjacent tube whereby to provide a deep welding opening and the strip being of width sufficient to provide a relatively wide root for said welding opening; and welding beads in the welding openings uniting adjacent tubes, tube-to-tube, each such bead overlying the inner edge of the spacing strip between a pair of adjacent tubes and having its inner surface lying between said median plane and the plane containing the innermost surfaces of the tubes to cooperatewith the exposed portions of the tubes in completing the inner surface of the water wall.

EDWARD CORBIN CHAPMAN.

References Cited in the file of this patent iifii i'ilii STATES PATENTS Number Name Date 1,499,770 Gruenfeldt July 1, 1924 1,540,270 May June 2, 1.925 1,702,058 Murray Feb. 12, 1920 1,775,321 Reed Sept. 9,1930 1,791,064 Murray Feb. 3, 1931 1,841,? 62 Samesreuther et al. Jan. 19, 192 2 1,872,240 Burnish Aug. 1932 1,980,561, Wagner Nov. 13, 1934 2,000,906 Turner May 14, 11935 2,327,750 Turner Aug. 2 1, 1943 2,354,222 shellenberg ei July 25, 1944 FOREIGN PATENTS Number Country Date 145,430 Austria Apr. 25, 1936 240,189 Switzerland 1 Dec. 15, 1945 394,233 Great Britain June 22, 1933 

